The present invention relates to a novel resin composition comprising a polyarylate and/or polyester carbonate and a polyimide and to a molded product thereof More specifically, it relates to a novel resin composition which comprises a polyarylate and/or polyester carbonate and a polyimide and has excellent heat resistance, moldability and dimensional stability and to a molded product thereof.
Polyimides typified by KAPTON are used in a wide variety of industrial fields such as an electronic field thanks to their high heat resistance. However, the polyimides generally have poor moldability and low dimensional stability due to their high hygroscopicity, and are inferior in optical transparency because they are colored red brown. Meanwhile, polyarylates and polycarbonates are materials having excellent dimensional stability against moisture absorption and excellent optical transparency. However, as these materials have a glass transition temperature of 200xc2x0 C. at best, they have limitation in heat resistance. Therefore, solder resistance cannot be expected from these materials and the materials do no have satisfactory performance as the next generation optical material expected for use in photoelectric printed boards.
A blend of a polyarylate and a polyether imide is disclosed by EP117326A and EP33011B/U.S. Pat. No. 4,250,279 as attempts to combine the characteristic properties of a polyimide and a polyarylate. Out of these, EP33011B/U.S. Pat. No. 4,250,279 reports that the blend is not always transparent, depending on the ratio of the polyarylate to the polyimide. EP256761A/U.S. Pat. No. 5,084,526 and U.S. Pat. No. 4,879,354 disclose a compatible blend comprising a polyarylate and a polycarbonoimide (aromatic ether amide imide polymer) which contains an aromatic diamine as a diamine component. Although this blend is amorphous, as the contained aromatic ether amide imide has a structure derived from a bisphenol A derivative, the blend has a low Tg of 220 to 270xc2x0 C. and has limitation in improving the heat resistance of the polyarylate while retaining compatibility. Therefore, a large amount of the aromatic ether amide imide is required to improve heat resistance, thereby sharply increasing melt viscosity and making molding difficult. EP594386A1/U.S. Pat. No. 5,387,639 discloses a thermoplastic molding composition which comprises a polyester carbonate resin and/or polyarylate resin and polyether imide resin. EP117327A discloses a composition which is a blend of a polyarylate, polyether imide and thermoplastic polymer compatibile with these.
WO 98/23682 discloses a thermoplastic resin composition which comprises a polyimide and an aromatic polyester.
The above blend compositions have a glass transition temperature Tg of 220xc2x0 C. at best and a blend composition having sufficiently high resistance to soldering heat has not been ever reported.
Studies on a blend of a liquid crystal polyarylate and a polyimide (Polymer vol. 36, pp. 259-266, 1995) have been reported but the blend is a heterogeneous material which is a non-compatible or partly compatible blend and the reported blend compositions are unsatisfactory in terms of heat resistance.
It is an object of the present invention to provide a novel resin composition which comprises a polyarylate and a polyimide.
It is another object of the present invention to provide a resin composition as a novel heat resistant material having excellent heat resistance, moldability and dimensional stability.
It is still another object of the present invention to provide a resin composition which has excellent heat resistance and transparency.
It is a further object of the present invention to provide a molded product of the above resin composition of the present invention.
Other objects and advantages of the present invention will become apparent from the following description.
According to the present invention, firstly, the above objects and advantages of the present invention are attained by a resin composition comprising:
(A) a polyimide comprising a recurring unit represented by the following formula (1): 
xe2x80x83wherein Ar0 is an aromatic hydrocarbon group having 6 to 15 carbon atoms, and R1 is at least one group selected from the group consisting of a divalent residual group obtained by removing two amino groups from an aliphatic diamine having 2 to 30 carbon atoms and a divalent residual group obtained by removing two amino groups from an alicyclic diamine having 4 to 30 carbon atoms, and
(B) at least one polymer selected from the group consisting of a polyarylate comprising at least one recurring unit selected from the group consisting of a recurring unit represented by the following formula (2-1): 
xe2x80x83wherein Ar1 is an aromatic hydrocarbon group having 6 to 18 carbon atoms and Ar2 is an aromatic hydrocarbon group having 6 to 30 carbon atoms or a combination of the aromatic hydrocarbon group and an aliphatic hydrocarbon group having 2 to 10 carbon atoms, and a recurring unit represented by the following formula (2-2): 
xe2x80x83wherein Ar3 is an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a polyester carbonate comprising one of the above recurring units and a recurring unit represented by the following formula (2-3): 
xe2x80x83wherein Ar4 is an aromatic hydrocarbon group having 6 to 30 carbon atoms, the amount of the polyimide (A) being 0.05 to 99.95 wt % and the amount of the polymer (B) being 99.95 to 0.05 wt % based on the total weight of the polyimide (A) and the polymer (B).
Secondly, the above objects and advantages of the present invention are attained by a molded product of the above resin composition of the present invention. The molded product is an article used for a specific purpose and having a three-dimensional form, and includes films and sheets.
The polyimide used in the present invention consists of a recurring unit represented by the above formula (1).
In the formula (1), Ar0 is an aromatic hydrocarbon group having 6 to 15 carbon atoms. Examples of the aromatic hydrocarbon group include groups represented by the following formulas: 
wherein X is a single bond, carbonyl group, sulfonyl group, alkylene group having 1 to 3 carbon atoms or haloalkylene group having 1 to 3 carbon atoms.
They may be existent in the polymer chain alone or in combination of two or more.
Out of these, groups represented by the following formulas are preferred: 
groups represented by the following formulas are more preferred: 
and groups represented by the following formula are particularly preferred: 
In the above formula (1), R1 is the divalent residual group obtained by removing two amino groups from an aliphatic diamine having 2 to 30 carbon atoms or the divalent residual group obtained by removing two amino groups from an alicyclic diamine having 4 to 30 carbon atoms. R1 may be alone or in combination of two or more selected from these residual groups.
Examples of the residual group obtained by removing two amino groups from an aliphatic diamine having 2 to 30 carbon atoms include groups represented by the following formula:
xe2x80x94(CH2)nxe2x80x94
wherein n is a number of 2 to 30, such as ethylene, propylene, trimethylene, tetramethylene, dimethylpropylene, hexamethylene, octamethylene, decamethylene, undecamethylene, dodecamethylene, eicosamethylene and triacontamethylene; and 2,2,4-trimethylhexamethylene diamine and 2,4,4-trimethylhexamethylene diamine. Another example is 
Out of these, the groups represented by the above formula xe2x80x94(CH2)nxe2x80x94 and by the formula 
are preferred.
Examples of the divalent residual group obtained by removing two amino groups from an alicyclic diamine having 4 to 30 carbon atoms include groups represented by the following formulas: 
Out of these, groups represented by the following formulas are preferred: 
In the present invention, the recurring unit represented by the above formula (1) is preferably a recurring unit represented by the following formula (1)-1: 
wherein Ar0 is as defined in the above formula (1), or a recurring unit represented by the following formula (1)-2: 
wherein Ar0 is as defined in the above formula (1), and m is an integer of 9 to 12, particularly preferably a recurring unit represented by the following formula (1)-1-1: 
or a recurring unit represented by the following formula (1)-2-1: 
wherein mxe2x80x2 is 10 and/or 12.
The above polyimide may be produced by known methods. The methods include one in which a polyamide acid is obtained from a tetracarboxylic dianhydride as a raw material capable of deriving the above Ar0 and a diamine capable of deriving the above R1 and heated to close the ring thereof, one in which ring closure is chemically carried out using an acid anhydride and a chemical ring closing agent such as pyridine, carbodiimide or triphenyl phosphate, and one in which the above tetracarboxylic dianhydride and a diisocyanate capable of deriving the above R1 are polymerized by heating and decarboxylation.
Examples of the tetracarboxylic dianhydride used in the above methods include pyrromellitic dianhydride, 3,3xe2x80x2,4,4xe2x80x2-benzophenone tetracarboxylic dianhydride, 3,3xe2x80x2-4,4xe2x80x2-biphenyltetracarboxylic dianhydride and 3,3xe2x80x2,4,4xe2x80x2-diphenylsulfone tetracarboxylic dianhydride.
Examples of the diamine include ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 2,2-dimethyl-1,3-propanediamine, 1,6-hexamethylenediamine, 1,8-octamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, isophoronediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 1,4-cyclohexanedimethylamine, 4-methyl-1,3-cyclohexanediamine and paraxylylenediamine.
Examples of the diisocyanate component include ethylene diisocyanate, 1,2-propane diisocyanate, 1,3-propane diisocyanate, 2,2-dimethyl-1,3-propane diisocyanate, 1,6-hexamethylene diisocyanate, 1,8-octamethylene diisocyanate, 1,10-decamethylene diisocyanate, 1,11-undecamethylene diisocyanate, 1,12-dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, 1,4-cyclohexane dimethylisocyanate, 4-methyl-1,3-cyclohexane diisocyanate and paraxylylene diisocyanate.
The molecular weight of the polyimide in the present invention is not particularly limited. Generally speaking, when the polyimide dissolves in a mixed solvent of phenol/tetrachloroethane (weight ratio of 6/4), it preferably has an intrinsic viscosity measured at a temperature of 35xc2x0 C. and a concentration of 1.2 g/dl of 0.05 to 12 dl/g. The lower limit is more preferably 0.07, much more preferably 0.10 and the upper limit is more preferably 10.
The polyarylate used in the present invention consists of at least one of a recurring unit represented by the above formula (2-1) and a recurring unit represented by the above formula (2-2).
In the above formula (2-1), Ar1 is an aromatic hydrocarbon group having 6 to 18 carbon atoms. The aromatic hydrocarbon group is a group represented by the following formula: 
wherein Y1 is a group selected from the group consisting of an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms and halogen atom, and y is a number of 0 to 4, with the proviso that when y is 2 to 4, Y1""s may be the same or different, or a group represented by the following formula: 
wherein Y1 and y are as defined hereinabove, with the proviso that Y1""s may be the same or different, the total of two y""s is not larger than 6, and two bonding hands may come out from any position excluding the peri-position of a naphthalene ring.
The aliphatic hydrocarbon group represented by Y1 in the above formula has 1 to 6 carbon atoms, as preferably exemplified by alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl and hexyl. The alkyl groups may be linear or branched (for example, neopentyl group) The alicyclic hydrocarbon group represented by Y1 has 6 to 12 carbon atoms, as exemplified by cyclohexyl, decalyl and cyclohexyl cyclohexyl (dodecahydroxybiphenylyl). Further, the halogen atom represented by Y1 is preferably fluorine, chlorine or bromine y is an integer of 0 to 6. When y is an integer of 2 to 4, Y1""s may be the same or different. In the latter formula, the total of two y""s is not larger than 6. Preferred examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms represented by Ar1 include 1,4-phenylene, 1,3-phenylene, 2,6-naphthylene, 2,7-naphthylene and 2,3-naphthylene.
Out of these, 1,4-phenylene, 1,3-phenylene and 2,6-naphthylene are more preferred.
Ar1 may be alone or in combination of the above groups, particularly preferably a combination of 1,4-phenylene and 1,3-phenylene.
In the above formula (2-1), Ar2 is an aromatic hydrocarbon group having 6 to 30 carbon atoms or a combination of the aromatic hydrocarbon group and an aliphatic hydrocarbon group having 2 to 10 carbon atoms. The aromatic hydrocarbon group having 6 to 30 carbon atoms is a group represented by the following formula: 
wherein Y1 is a group selected from the group consisting of an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms and halogen atom, and y is a number of 0 to 4, with the proviso that when y is 2 to 4, Y1""s may be the same or different, or a group represented by the following formula: 
wherein Z is a group selected from the group consisting of a single bond, ether bond, carbonyl group, sulfonyl group, aliphatic hydrocarbon group having 1 to 10 carbon atoms, haloaliphatic hydrocarbon group having 1 to 10 carbon atoms, alicyclic hydrocarbon group having 6 to 10 carbon atoms and haloalicyclic hydrocarbon group having 6 to 10 carbon atoms, Y2""s are each independently an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms or halogen atom, and x""s are each independently a number of 0 to 4.
Examples of the phenylene group and substituted phenylene group in the former formula are the same as those enumerated for Ar1.
In the latter formula, examples of the aliphatic hydrocarbon group having 1 to 10 carbon atoms and the alicyclic hydrocarbon group having 6 to 10 carbon atoms represented by Z and Y2 are the same divalent groups as those enumerated for Y1 in Ar1, such as 1,2-ethylene group and 1,4-cyclohexylene group. Examples of the haloaliphatic hydrocarbon group having 1 to 10 carbon atoms and haloalicyclic hydrocarbon group having 6 to 12 carbon atoms are halo-substitution products of the above aliphatic hydrocarbon groups and alicyclic hydrocarbon groups. Preferred examples of the halo-substitution products and halogen atom represented by Y2 include fluorine, chlorine and bromine. Two x""s are each independently a number of 0 to 4.
The aliphatic hydrocarbon group having 2 to 10 carbon atoms represented by Ar2 is preferably a group having no tertiary carbon atom such as methylene, ethylene, trimethylene, tetramethylene, hexamethylene, decamethylene or neopentylene. Neopentylene is particularly preferred. The aliphatic hydrocarbon group is used in combination with the above aromatic hydrocarbon group having 6 to 30 carbon atoms.
In the above formula (2-2), Ar3 is an aromatic hydrocarbon group having 6 to 18 carbon atoms. The aromatic hydrocarbon group having 6 to 18 carbon atoms is, for example, a group represented by the following formula: 
wherein Y1 is a group selected from the group consisting of an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms and halogen atom, and y is a number of 0 to 4, with the proviso that when y is 2 to 4, Y1""s may be the same or different.
Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms are the same as those enumerated for Ar1. Out of these, a 1,4-phenylene group is particularly preferred.
The polyarylate in the present invention may be polymerized by conventionally known methods. The methods include one in which an acid chloride derived from a dicarboxylic acid and a diphenol are polycondensed in the presence of a methylene chloride solvent, one in which a diphenyl ester derived from a dicarboxylic acid and a diphenol are melt polymerized in the presence of a catalyst, one in which a monooxy monocarboxylic acid ester is polycondensed in the presence of an alkali, and one in which a diphenyl dicarboxylate, diphenol and monooxy monocarboxylic acid ester are polycondensed in the presence of a catalyst.
Examples of the above dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2-methylterephthalic acid, 4-methylisophthalic acid, 2-chloroterephthalic acid, 2,6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid.
Examples of the monooxy monocarboxylic acid include 4-oxybenzoic acid and 6-oxynaphthoic acid.
Examples of the diphenol include
2,2-bis-(4-hydroxyphenyl)propane,
bis-(4-hydroxyphenyl)methane,
1,1-bis-(4-hydroxyphenyl)ethane,
1,2-bis-(4-hydroxyphenyl)ethane,
1,3-bis-(4-hydroxyphenyl)propane,
bis-(2-hydroxyphenyl)methane,
1,1-bis-(2-hydroxyphenyl)ethane,
1,2-bis-(2-hydroxyphenyl)ethane,
2,2-bis-(2-hydroxyphenyl)propane,
1,3-bis-(2-hydroxyphenyl)propane,
bis-(4-hydroxy-2,6-dimethyl-3-methoxyphenyl)methane,
1,1-bis-(4-hydroxy-2,6-dimethyl-3-methoxyphenyl)ethane,
1,2-bis-(4-hydroxy-2,6-dimethyl-3-methoxyphenyl)ethane,
2,2-bis-(4-hydroxy-2,6-dimethyl-3-methoxyphenyl)propane,
1,3-bis-(4-hydroxy-2,6-dimethyl-3-methoxyphenyl)propane,
bis-(4-hydroxyl-2-chlorophenyl)methane,
1,1-bis-(4-hydroxy-2-chlorophenyl)ethane,
1,2-bis-(4-hydroxy-2-chlorophenyl)ethane,
2,2-bis-(4-hydroxy-2-chlorophenyl)propane,
1,3-bis-(4-hydroxy-2-chlorophenyl)propane,
bis-(3-methyl-4-hydroxyphenyl)methane,
1,1-bis-(3-methyl-4-hydroxyphenyl)ethane,
1,2-bis-(3-methyl-4-hydroxyphenyl)ethane,
2,2-bis-(3-methyl-4-hydroxyphenyl)propane,
1,3-bis-(3-methyl-4-hydroxyphenyl)propane,
2,2-bis-(3-isopropyl-4-hydroxyphenyl)propane,
2,2-bis-(2-isopropyl-4-hydroxyphenyl)propane and
p-dihydroxybenzene.
The molecular weight of the polyarylate in the present invention is not particularly limited but the intrinsic viscosity measured in a mixed solvent of phenol/tetrachloroethane (weight ratio of 6/4) at a temperature of 35xc2x0 C. and a concentration of 1.2 g/dl of the polyarylate is preferably 0.1 to 10.0 dl/g. The lower limit is more preferably 0.15, much more preferably 0.25 and the upper limit is more preferably 7.
The polyester carbonate used in the present invention further contains a recurring unit represented by the above formula (2-3).
In the above formula (2-3), Ar4 is an aromatic hydrocarbon group having 6 to 30 carbon atoms. The aromatic hydrocarbon group having 6 to 30 carbon atoms is, for example, a group represented by the following formula: 
wherein Y1 is a group selected from the group consisting of an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms and halogen atom, and y is a number of 0 to 4, with the proviso that when y is 2 to 4, Y1""s may be the same or different, and/or a group represented by the following formula: 
wherein Z is a group selected from the group consisting of a single bond, ether bond, carbonyl group, sulfonyl group, aliphatic hydrocarbon group having 1 to 10 carbon atoms, haloaliphatic hydrocarbon group having 1 to 10 carbon atoms, alicyclic hydrocarbon group having 6 to 10 carbon atoms and haloalicyclic hydrocarbon group having 6 to 10 carbon atoms, Y2""s are each independently an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms or halogen atom, and x""s are each independently a number of 0 to 4.
Examples of the aromatic hydrocarbon groups are the same as those enumerated for Ar2 in the formula (2-1).
The above polyester carbonate in the present invention can be produced by a known method, for example, one in which an aromatic dihydroxy compound and phosgene are polycondensed in the presence of an alkali and then the obtained polycondensate is melt kneaded with the above polyarylate, or one in which a dicarboxylic acid, aromatic dihydroxy compound and diphenyl carbonate are polycondensed in the presence of a catalyst.
The molecular weight of the polyester carbonate in the present invention is not particularly limited but the intrinsic viscosity measured in a mixed solvent of phenol/tetrachloroethane (weight ratio of 6/4) at a temperature of 35xc2x0 C. and a concentration of 1.2 g/dl of the polyester carbonate is preferably 0.1 to 10.0 dl/g. The lower limit is more preferably 0.15, much more preferably 0.25 and the upper limit is more preferably 7.
The resin composition in the present invention comprises 0.05 to 99.95 wt % of the polyimide (A) and 99.95 to 0.05 wt % of the polymer (B) based on the total weight of the polymer (B) and the polyimide (A). When the amount of the polymer (B) is smaller than 0.05 wt %, an effect may not be obtained by adding the polyimide (A) to the polymer (B) and heat resistance may not be improved fully. When the amount of the polymer (B) is larger than 99.95 wt %, an effect may not be obtained by blending the polymer (B) and the moisture absorption and water absorption properties of the polyimide (A) may not be improved.
Based on the same standard, the amount of the polymer (B) is preferably 2 to 95 wt %, more preferably 5 to 90 wt %. Therefore, the amount of the polyimide (A) is preferably 98 to 5 wt %, more preferably 95 to 10 wt %.
It has been revealed that the above resin composition of the present invention having the following composition is particularly excellent in transparency.
The polyamide (A) comprises a recurring unit represented by the following formula (1)-1: 
wherein Ar0 is as defined in the above formula (1), and the polymer (B) is a polyarylate which comprises a recurring unit represented by the following formula (2-1)-1: 
wherein Ar1 is as defined in the above formula (2-1), and Ar21 is at least one group selected from the group consisting of groups represented by the following formula: 
wherein Z is a group selected from the group consisting of a single bond, ether bond, carbonyl group, sulfonyl group, aliphatic hydrocarbon group having 1 to 10 carbon atoms, haloaliphatic hydrocarbon group having 1 to 10 carbon atoms, alicyclic hydrocarbon group having 6 to 10 carbon atoms and haloalicyclic hydrocarbon group having 6 to 10 carbon atoms, Y2""s are each independently an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms or halogen atom, and x""s are each independently a number of 0 to 4.
The above polyarylate comprises more preferably a recurring unit represented by the following formula (2-1)-2: 
wherein Ar1 is as defined in the above formula (2-1), particularly preferably a recurring unit of the above formula (2-1)-2 in which Ar1 is a 1,4-phenylene group and/or 1,3-phenylene group.
The above resin composition having excellent transparency has a light absorption coefficient at a wavelength of 400 to 800 nm of preferably 200 cmxe2x88x921 or less, more preferably 100 cmxe2x88x921 or less, particularly preferably 0 to 50 cmxe2x88x921. When this value is larger than 200 cmxe2x88x921, coloring becomes marked. The expression xe2x80x9clight absorption coefficientxe2x80x9d as used herein means a coefficient a based on the condition that light transmittance follows Lambert""s law represented by the following equation:
I/I0=exp(xe2x88x92xcex1d)
wherein I is the intensity of transmitted light at a measurement wavelength, I0 is the intensity of incident light, and d is the thickness of a resin composition (unit: cm).
It has also been found that the resin composition of the present invention having the following composition is particularly excellent in transparency.
The polyimide (A) consists of a recurring unit represented by the above formula (1)-1 and the polymer (B) is a polyester carbonate which consists of a recurring unit represented by the following formula (2-1)-1xe2x80x2: 
wherein Ar1 is as defined in the above formula (2-1), and Ar22 is a group represented by the following formula: 
wherein Z is a group selected from the group consisting of a single bond, ether bond, carbonyl group, sulfonyl group, aliphatic hydrocarbon group having 1 to 10 carbon atoms, haloaliphatic hydrocarbon group having 1 to 10 carbon atoms, alicyclic hydrocarbon group having 6 to 10 carbon atoms and haloalicyclic hydrocarbon group having 6 to 10 carbon atoms,. Y2""s are each independently an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms or halogen atom, and x""s are each independently a number of 0 to 4, and a recurring unit represented by the following formula (2-3)-1: 
wherein Ar41 is a group represented by the following formula: 
wherein Z is a group selected from the group consisting of a single bond, ether bond, carbonyl group, sulfonyl group, aliphatic hydrocarbon group having 1 to 10 carbon atoms, haloaliphatic hydrocarbon group having 1 to 10 carbon atoms, alicyclic hydrocarbon group having 6 to 10 carbon atoms and haloalicyclic hydrocarbon group having 6 to 10 carbon atoms, Y2""s are each independently an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms or halogen atom, and x""s are each independently a number of 0 to 4.
The above polyester carbonate preferably comprises a recurring unit represented by the following formula (2-1)-2: 
wherein Ar1 is as defined in the above formula (2-1), and a recurring unit represented by the following formula (2-3)-1xe2x80x2: 
particularly preferably comprises a recurring unit of the above formula (2-1)-2 in which Ar1 is a 2,6-naphthylene group and a recurring unit of the above formula (2-3)-1xe2x80x2.
The resin composition which comprises a polyester carbonate and has excellent transparency shows the same value of light absorption coefficient as the above resin composition which comprises a polyarylate and has excellent transparency.
It has been made clear that out of the above resin compositions of the present invention, a resin composition having the following composition is almost opaque without transparency.
The polyimide (A) comprises a recurring unit represented by the following formula (1)-3: 
wherein Ar0 is as defined in the above formula (1) and n is a number of 2 to 30, and the polymer (B) is a polyarylate comprising a recurring unit represented by the following formula (2-1)-4: 
wherein Ar1 is as defined in the above formula (2-1), and Ar23 is selected from a group represented by the following formula: 
wherein Y1 is a group selected from the group consisting of an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms and halogen atom, and y is a number of 0 to 4, with the proviso that when y is 2 to 4, Y1""s may be the same or different, and a group represented by the following formula: 
wherein Z is a group selected from the group consisting of a single bond, ether bond, carbonyl group, sulfonyl group, aliphatic hydrocarbon group having 1 to 10 carbon atoms, haloaliphatic hydrocarbon group having 1 to 10 carbon atoms, alicyclic hydrocarbon group having 6 to 10 carbon atoms and haloalicyclic hydrocarbon group having 6 to 10 carbon atoms, Y2""s are each independently an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms or halogen atom, and x""s are each independently a number of 0 to 4.
The above polyarylate preferably comprises a recurring unit represented by the following formula (2-1)-5: 
wherein Ar1 is as defined in the above formula (2-1), and a recurring unit represented by the following formula (2-1)-6: 
wherein Ar1 is as defined in the above formula (2-1), particularly preferably comprises a recurring unit of the formula (2-1)-5 in which Ar1 is a 1,3-phenylene group and a recurring unit of the formula (2-1)-6 in which Ar1 is a 1,3-phenylene group.
Alternatively, the polyimide (A) comprises a recurring unit represented by the following formula (1)-3: 
wherein Ar0 is as defined in the above formula (1) and n is a number of 2 to 30, and the polymer (B) is a polyarylate which comprises a recurring unit represented by the following formula (2-1)-4: 
wherein Ar1 is as defined in the above formula (2-1), and Ar23 is selected from a group represented by the following formula: 
wherein Y1 is a group selected from the group consisting of an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms and halogen atom, and y is a number of 0 to 4, with the proviso that when y is 2 to 4, Y1""s may be the same or different, and/or a group represented by the following formula: 
The above polyarylate preferably comprises a recurring unit represented by the following formula (2-1)-7: 
wherein Ar1 is as defined in the above formula (2-1), and a recurring unit represented by the following formula 
wherein Ar1 is as defined in the above formula (2-1), particularly preferably comprises a recurring unit of the above formula (2-1)-7 in which Ar1 is a 1,3-phenylene group and a recurring unit of the above formula (2-1)-6 in which Ar1 is a 1,3-phenylene group.
As described above, the opaque resin composition has a light absorption coefficient at a wavelength of 400 nm to 800 nm of more than 200 cmxe2x88x921.
Also, it has been made clear that the above resin composition of the present invention having the following composition is semi-opaque.
The polyimide (A) comprises a recurring unit represented by the following formula (1)-4: 
wherein Ar0 is as defined in the above formula (1) and R11 is a group represented by the following formula: 
wherein n is an integer of 2 to 30, and the polymer (B) is an polyarylate which comprises a recurring unit represented by the following formula (2-1)-1: 
wherein Ar1 is as defined in the above formula (2-1) and Ar21 is selected from a group represented by the following formula: 
wherein Y1 is a group selected from the group consisting of an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms and halogen atom, and y is a number of 0 to 4, with the proviso that when y is 2 to 4, Y1""s may be the same or different, and a group represented by the following formula: 
wherein Z is a group selected from the group consisting of an ether bond, carbonyl group, sulfonyl group, aliphatic hydrocarbon group having 1 to 10 carbon atoms, haloaliphatic hydrocarbon group having 1 to 10 carbon atoms, alicyclic hydrocarbon group having 6 to 10 carbon atoms and haloalicyclic hydrocarbon group having 6 to 10 carbon atoms, Y2""s are each independently an aliphatic hydrocarbon group having 1 to 6 carbon atoms, alicyclic hydrocarbon group having 6 to 12 carbon atoms or halogen atom, and x""s are each independently a number of 0 to 4.
The above polyarylate preferably comprises a recurring unit represented by the following formula (2-1)-2: 
wherein Ar1 is as defined in the above formula (2-1), and a recurring unit represented by the following formula (2-1)-3: 
wherein Ar1 is as defined in the above formula (2-1), particularly preferably comprises a recurring unit of the above formula (2-1)-2 in which Ar1 is a 1,3-phenylene group and a recurring unit of the above formula (2-1)-3 in which Ar1 is a 1,3-phenylene group.
The polymer (B) and the polyimide (A) in the present invention are preferably soluble in an organic solvent. When they are soluble in an organic solvent, the resin composition of the present invention can be molded even though it has a high transition temperature.
Examples of the organic solvent include hydrocarbon halide solvents such as dichloromethane and chloroform; cyclic ether solvents such as tetrahydrofuran, 1,3-dioxolan and 1,4-dioxane; amide solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide and N,N-dimethylformamide; sulfoxide solvents such as dimethyl sulfoxide; and phenol solvents such as phenol, m-cresol, o-chlorophenol, o-dichlorophenol and 2,4,6-trichlorophenol.
In the resin composition of the present invention, the polymer (B) and the polyimide (A) are preferably compatible with each other. In the resin composition of the present invention, xe2x80x9ccompatiblexe2x80x9d can be judged independently (1) in a state where the resin composition is solidified at a temperature (room temperature) lower than the melting points of the polymer (B) and the polyimide (A) or the organic solvent is removed after the components (A) and (B) are dissolved in the organic solvent, that is, in the state of a molded product, (2) in a molten state where the polymer (B) and the polyimide (A) are molten at a temperature higher than their melting points, or (3) a state where the polymer (B) and the polyimide (A) are dissolved in an organic solvent which can dissolve both.
When the composition is used for its differential scanning calorimetry (DSC) or dynamic viscoelasticity measurement in the above state (1), at least one glass transition temperature point of the measured resin composition is observed and shifted to a position close to the glass transition temperature of one of the component (A) and component (B).
When only one point is observed, the known Fox equation a (following equation (1)-1) or (1)-2, 3 and 4 are satisfied:
1/TgC=wA(1/TgA)+wB(1/TgB)xe2x80x83xe2x80x83(1)-1
wherein TgC is the glass transition temperature of the measured composition, TgA and TgB are the glass transition temperatures of the polyimide (A) and the polymer (B), and wA and wB are the weight percentages of the component (A) and the component (B) contained in the composition, respectively.
when TgA greater than  greater than TgB, TgB less than TgC less than TgA (1)-2
when TgB greater than  greater than TgA, TgA less than TgC less than TgB (1)-3
when TgA=TgB, TgA=TgC=TgB (1)-4
xe2x80x83wherein TgC, TgA and TgB are as defined in (1)-1.
When two glass transition temperature points are observed, the following equations (1)-5 and 6 are satisfied.
when TgA greater than  greater than TgB, TgB less than TgC1, TgC2 less than TgA (1)-5
when TgB greater than  greater than TgA, TgA less than TgC1, TgC2 less than TgB (1)-6
xe2x80x83wherein TgC1 and TgC2 are the glass transition temperatures of the measured composition and TgA and TgB are as defined in (1)-1.
Particularly when the polymer (B) and the polyimide (A) have transparency, the components (A) and (B) are judged as compatible with each other if the composition has the same or higher light transmittance than the component (A) or (B) which has a lower light transmittance than the other.
In the state (2), the components (A) and (B) are judged as compatible with each other when turbidity or liquid-liquid phase separation is not observed and they are transparent.
In the state (3), the components (A) and (B) are judged as compatible with each other when turbidity or liquid-liquid phase separation is not observed by the measurement of light transmittance (80% or more) and haze meter (haze value of 20 or less) of a solution comprising 1 to 20 wt % of the composition.
In the resin composition of the present invention, the glass transition temperature is preferably 220xc2x0 C. or more, more preferably 260xc2x0 C. or more. When the glass transition temperature is lower than 220xc2x0 C., the best use of the heat resistance of the polymer (B) and the polyimide (A) is not made and the characteristic properties of the resin cannot be fully obtained.
As for the method of producing the resin composition of the present invention, when the polymer (B) and the polyimide (A) are both soluble in an organic solvent, they are dissolved and mixed together in the organic solvent which is then removed after shaping. This method is very effective when the glass transition temperature of the resin composition of the present invention is high. When the decomposition of the polymers does not occur and the temperature is within a range at which at least one of the polymers flows, a double-screw extruder may be used to mix these. Further, the resin composition of the present invention may also be produced by mixing together these polymers while polymerizing the polymer (B) in the presence of the polyimide (A).
The resin composition of the present invention may contain various additives as required. The additives include a fibrous reinforcing agent such as glass fiber, metal fiber, aramide fiber, ceramic fiber, potassium titanate whisker or carbon fiber; filler such as talc, calcium carbonate, mica, clay, titanium oxide, aluminum oxide or metal powders; thermal stabilizer or oxidation stabilizer typified by phosphates and phosphites, optical stabilizer, ultraviolet light absorber, lubricant, pigment, flame retardant, flame retardant aid, plasticizer and crystal nucleating agent.
According to the present invention, a resin composition having sufficiently high heat resistance and high glass transition temperature which cannot be obtained by the polyarylate alone and a homogeneous molded product thereof can be obtained with excellent moldability. Similarly, a resin composition having excellent moisture and water absorption properties and heat resistance which cannot be obtained by the polyimide alone and a molded product thereof can be obtained. Further,according to the present invention, a resin composition and a molded product thereof having a desired glass transition temperature which falls within the glass transition temperature ranges of both of the polymers can be designed, making use of the additive property of glass transition temperatures by suitably selecting the glass transition temperatures of the polymer (B) and the polyimide (A) and suitably setting the ratio of the polymer (B) to the polyimide (A).
The resin composition and molded product thereof of the present invention can be applied in flexible solar cell substrates, liquid crystal alignment films, optical substrate materials and optical elements, making use of the above excellent characteristic properties and are therefore of great industrial significance.
The transparent resin composition and molded product thereof can be particularly applied in flexible printed boards, rigid printed boards, photoelectric printed boards, sealing agents, interlayer insulating films and optical waveguide materials, making use of the above excellent characteristic properties and are therefore of great industrial significance.